2,321 research outputs found
Towards establishing Lepton Flavour Universality violation in decays
Rare semileptonic transitions provide some of the
most promising frameworks to search for new physics effects. Recent analyses of
these decays have indicated an anomalous behaviour in measurements of angular
distributions of the decay and
lepton-flavour-universality observables. Unambiguously establishing if these
deviations have a common nature is of paramount importance in order to
understand the observed pattern. We propose a novel approach to independently
and complementary probe this hypothesis by performing a simultaneous amplitude
analysis of and decays. This method enables the direct determination of
observables that encode potential non-equal couplings of muons and electrons,
and are found to be insensitive to nonperturbative QCD effects. If current
hints of new physics are confirmed, our approach could allow an early discovery
of physics beyond the standard model with LHCb run II data sets.Comment: 6 pages, 7 figures. Matching the journal versio
On the Juno Radio Science Experiment: models, algorithms and sensitivity analysis
Juno is a NASA mission launched in 2011 with the goal of studying Jupiter.
The probe will arrive to the planet in 2016 and will be placed for one year in
a polar high-eccentric orbit to study the composition of the planet, the
gravity and the magnetic field. The Italian Space Agency (ASI) provided the
radio science instrument KaT (Ka-Band Translator) used for the gravity
experiment, which has the goal of studying the Jupiter's deep structure by
mapping the planet's gravity: such instrument takes advantage of synergies with
a similar tool in development for BepiColombo, the ESA cornerstone mission to
Mercury. The Celestial Mechanics Group of the University of Pisa, being part of
the Juno Italian team, is developing an orbit determination and parameters
estimation software for processing the real data independently from NASA
software ODP. This paper has a twofold goal: first, to tell about the
development of this software highlighting the models used, second, to perform a
sensitivity analysis on the parameters of interest to the mission.Comment: Accepted for publication in MONTHLY NOTICES of the Royal Astronomical
Society 2014 October 31. Received 2014 July 28; in original form 2013 October
Analysis of attractor distances in Random Boolean Networks
We study the properties of the distance between attractors in Random Boolean
Networks, a prominent model of genetic regulatory networks. We define three
distance measures, upon which attractor distance matrices are constructed and
their main statistic parameters are computed. The experimental analysis shows
that ordered networks have a very clustered set of attractors, while chaotic
networks' attractors are scattered; critical networks show, instead, a pattern
with characteristics of both ordered and chaotic networks.Comment: 9 pages, 6 figures. Presented at WIRN 2010 - Italian workshop on
neural networks, May 2010. To appear in a volume published by IOS Pres
Upgrading the lipid fraction of foods of animal origin by dietary means: rumen activity and presence of trans fatty acids and CLA in milk and meat
The recent literature dealing with the effect of the diet on the quality of milk and meat fat is reviewed. Some aspects ofthe rumen metabolism of lipids are dealt with: lipolysis, bio-hydrogenation, synthesis of microbial fatty acids and inhibitionmechanisms on fermentation. Firstly, the influence of forage is considered. Pasture is the best forage, better if highhill pasture, as compared to hay and silage: short chain fatty acids (SCFA) (shorter than C10) are increased, mediumchain fatty acids (MCFA) (C12 through C16) are decreased, oleic (OA), linoleic (LA) and linolenic (LNA) acids are increasedand so are the conjugated linoleic acid pool of isomers (CLA) and n-3 polyunsaturated fatty acids (n-3 PUFA). Secondly,the energy supplementation of diets with fats is looked at. Animal fats depress milk yield and SCFA, while OA is increasedbecause of the enhanced activity of mammary Δ9 desaturase. Fish oil depresses milk yield as well, but promotes CLA andn-3 PUFA. If animal fats are protected against rumen bacteria, milk yield and milk fat depression are avoided. Vegetablefats are richer in unsaturated fatty acids (UFA), thus more susceptible to the rumen bio-hydrogenation. As calcium soapsor inside whole seeds, plant fats are protected and CLA is increased. CLA is an important component of fat. In ruminantsit comes from the desaturation of vaccenic acid (VA) both in rumen and udder; and the yield of VA depends on the dietquality. In conclusion, simple directions are given on how to improve the quality of animal fat by dietary means, withoutaffecting yield
On the concept of medium: An empirical study
The media are a fundamental object of communication studies, but do we agree on the definition of this term? Since the 1990s, technological convergence has modified the mediascape and complicated the distinction between technical device and communication channel. Today, people can read the newspaper on a smartphone and watch television on a computer screen—a situation that makes it compelling to reflect on what a medium actually is. To discover whether agreement on this matter exists in academia, we consulted members of the editorial boards of some of the leading journals in the communication field. Based on the results of a two-step survey, the article reflects on the theoretical status of media studies and some features of the field
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